question about brass flow...

[Brendon Potts]

So, I just put some Paragon dropouts in some fork legs that I was pretty sure were chromoly, and I checked with a magnet to make sure but when I went to braze them in with brass, the brass just wouldn't flow on the dropout, at least not well. This made me wonder if I was an idiot (pretty sure that has to answered in the affirmative), but I'm trying to figure out how, so I don't make this mistake again. As I said, because I recently had this issue with a fork crown (I'm getting lots of practice with various fork parts!), I checked the dropouts with magnets before going ahead with the brazing because I've had them around for who knows how long, and didn't label them. I'm wondering if there's any way they might be chromoly, but still not flow. Did I not clean them well enough? I've done lots of dropouts, including some paragon rear ones a few minutes before these, and they've come out wonderfully. I'm looking for any input on how better to identify 17/4 stainless (and any other ones used for bikes, because some, like the Pacenti crown, seem to still be magnetic to some extent). Also, I'm assuming it's a bad idea to try and salvage these legs in any way. I tried not to cook things too much, but I made sure everything was plenty hot. Forgive the long-windedness, and thanks a bunch!

[arregui]

Hi Brendon,

Don´t trust magnets. Magnetic permeability depends on the type of SS. Make sure to mark mild and SS when you receive it form supplier. Store in different places.
I have a little box with bits that I'm not sure what they are because i didn't do it before.

Best,

Andrés

[steve garro]

Rust test?

Of course there is the comparison of sparks but you have grind them.

http://www.sweethaven02.com/BldgCons.../painti132.gif

- Garro.

[Eric Estlund]

Mark stuff when you order and receive it- inventory control.

[Mark Kelly]

I'd try wetting the parts with acidified hydrogen peroxide, which will rust the non-stainless pretty fast. Won't harm the stainless: we use it as a non-rinse sterilant in brewing and wineries.

Warning: don't get it on your skin; stings like a MOFO.

[steve garro]

IMG_6677.JPG

Mark stuff when you order and receive it- inventory control.

Keep it under guard!

- Garro.

[Brendon Potts]

Thanks all...yeah, the obvious thing to do would be mark and keep good tabs on what's what, but that didn't happen with these. Oh well! And Steve, I don't have any of those handy little soldiers around! Dang! That guy looks like he's brass himself, so he could probably tell me what was what if I got into this situation again.... Well, thanks again for the suggestions.

[steve garro]

Thanks all...yeah, the obvious thing to do would be mark and keep good tabs on what's what, but that didn't happen with these. Oh well! And Steve, I don't have any of those handy little soldiers around! Dang! That guy looks like he's brass himself, so he could probably tell me what was what if I got into this situation again.... Well, thanks again for the suggestions.

Hey - the dropouts you did here in the shop were done with 45% from Aufhauser- Brazing, Welding, Soldering & Metallizing Filler Metals
FYI

Rock On!
- Garro.

[ParagonMachineWorks]

So, I just put some Paragon dropouts in some fork legs that I was pretty sure were chromoly, and I checked with a magnet to make sure but when I went to braze them in with brass, the brass just wouldn't flow on the dropout, at least not well. This made me wonder if I was an idiot (pretty sure that has to answered in the affirmative), but I'm trying to figure out how, so I don't make this mistake again. As I said, because I recently had this issue with a fork crown (I'm getting lots of practice with various fork parts!), I checked the dropouts with magnets before going ahead with the brazing because I've had them around for who knows how long, and didn't label them. I'm wondering if there's any way they might be chromoly, but still not flow. Did I not clean them well enough? I've done lots of dropouts, including some paragon rear ones a few minutes before these, and they've come out wonderfully. I'm looking for any input on how better to identify 17/4 stainless (and any other ones used for bikes, because some, like the Pacenti crown, seem to still be magnetic to some extent). Also, I'm assuming it's a bad idea to try and salvage these legs in any way. I tried not to cook things too much, but I made sure everything was plenty hot. Forgive the long-windedness, and thanks a bunch!

If you have a part number, Paragon's website should provide the material it was made from. If not, I would be happy to try and help; pictures are worth 1000 words!

[Brendon Potts]

Steve, yeah, I know, but I have been trying to use brass where possible for dropouts lately--at least where I think they'll work with it! And Sam, yeah, I've had these for a while now, and I don't know what happened to the baggie they came in or any other identification. I'll take a picture later, but from their looks, they appear to have the smaller eyelets which look like the 4130 ones on paragon's website (DR2050), but maybe there is no difference between those and DR1050 in reality. It looks like the DR1050s have larger eyelets, but these are older so maybe they're different than the current ones. In any case, I know I need to redo this, so that much is clear, and that means I should go get to work! Thanks again all!

[ParagonMachineWorks]

...yeah, I've had these for a while now, and I don't know what happened to the baggie they came in or any other identification. I'll take a picture later, but from their looks, they appear to have the smaller eyelets which look like the 4130 ones on paragon's website (DR2050), but maybe there is no difference between those and DR1050 in reality. It looks like the DR1050s have larger eyelets, but these are older so maybe they're different than the current ones. In any case, I know I need to redo this, so that much is clear, and that means I should go get to work! Thanks again all!

DR2050 and DR1050 have the same geometry, so eyelet size won't help identify them against each other. I've made a note of this so our next batch will have an identifier on the stainless version (something we are trying to incorporate into all our products now). Due to the brass flow issues I would go ahead and assume they are DR1050 (17-4 stainless) dropouts. Here's a snap shot of the two sitting side by side. Another means of helping to identify what material the dropout is comes from tool markings. Our stainless version gets machined on both sides so you get tool marks (striations) on the back of dropout, as opposed to the 4130 version you just have a more speckled looking surface.

DR1050 vs DR2050.jpg

[steve garro]

Steve, yeah, I know, but I have been trying to use brass where possible for dropouts lately!

That's what we did here while you were working on bikes - I only use brass unless it's stainless - I was referring to YOUR bike - we used 45% on the Rockers

- Garro.

[Eric Estlund]

DR2050 and DR1050 have the same geometry, so eyelet size won't help identify them against each other. I've made a note of this so our next batch will have an identifier on the stainless version (something we are trying to incorporate into all our products now). Due to the brass flow issues I would go ahead and assume they are DR1050 (17-4 stainless) dropouts. Here's a snap shot of the two sitting side by side. Another means of helping to identify what material the dropout is comes from tool markings. Our stainless version gets machined on both sides so you get tool marks (striations) on the back of dropout, as opposed to the 4130 version you just have a more speckled looking surface.

DR1050 vs DR2050.jpg

That's great follow up from the parts maker!

Just a note- I have had paragon parts (not this part) that had a much more pronounced speckle pattern (pock marked?) on the non machined face of drop outs. These were always stainless parts.

[Brendon Potts]

Steve, yeah, that's what I meant, and I understood what you were talking about. Anyway, same page. Sam and Eric, thanks for both of those responses. I got these dropouts years (maybe) ago, which is why I lost track of what they were made of. And they didn't have machining marks on the back but they do have the speckle pattern, so I'm going to guess that they were a situation like Eric is talking about. Anyway, all cleared up in this case, and in the future, if in doubt I'll do use silver, and just try not to be in doubt much ;). But thanks again for that image, Sam! That's really helpful. it does seem like an identifier on parts couldn't hurt, just in case the builder's organizing system breaks down at any point.